to Alan's doctor.

Getting a moment's dizziness upon standing up suddenly, is probably due to the blood pressure medication.

But getting dizzy sitting in a chair doing nothing is another. If he bends over to pick something up from the floor,
that is similar to standing up, and may be part of the blood pressure med.

Momentary dizziness can be due to sinus congestion or a plugged up ear.
But it can also be from too low of blood pressure. Or from A-fib..in the heart.
I suggest you have Alan log these episodes with a time of day and where they happen. If it is A-fib, (atrial fibrillation) that can be serious. It is a good thing he is on anti-clotting therapy...that reduces the risk of A-fib.

After I had my baby, and was still in the hospital, they overmedicated my blood pressure which had been elevated. I started seeing spots when I looked at the white walls, and once I fainted sitting up. So they tapered one of the meds off, the hydralazine. I was very happy to see that one go..it was nasty.